High-Efficiency White Organic Light-Emitting Diodes Based on Phosphorescent Iridium Complex and 4,4'-Bis[N-1-napthyl-N-phenyl-amino]biphenyl Emitters
- 1 February 2007
- journal article
- Published by IOP Publishing in Japanese Journal of Applied Physics
- Vol. 46 (2R), 523
- https://doi.org/10.1143/jjap.46.523
Abstract
High-efficiency white organic light-emitting devices (WOLEDs) based on phosphorescent dye bis[2-(4-tert-butylphenyl)benzothiazolato-N,C2']iridium (acetylacetonate) [(t-bt)2Ir(acac)] doped 4,4'-bis(carbazol-9-yl) biphenyl (CBP) as a yellow-emitting layer together with blue fluorescent emitter and hole-transporting material 4,4'-bis[N-1-napthyl-N-phenyl-amino]biphenyl (NPB) were fabricated. In those devices with a simple structure, 2,9-dimethyl,-4,7-diaphenyl,1,10-phenanthroline (BCP) and tris(8-quinolinolato) aluminum (Alq) were used as hole-blocking and electron-transporting layers, respectively. The purity of white light can be adjusted by doping concentration and bias voltage. The device shows a maximum luminance of 7580 cd/m2 with a luminance efficiency of 4.32 cd/A and Commission International De L'Eclairage (CIE) coordinates of (0.319,0.342) at 13.5 V. A maximum luminance efficiency of 10.2 cd/A at a current density of 0.026 mA/cm2 was achieved.Keywords
This publication has 15 references indexed in Scilit:
- High-efficiency top-emissive white-light-emitting organic electrophosphorescent devicesApplied Physics Letters, 2005
- White organic light-emitting diode comprising of blue fluorescence and red phosphorescenceApplied Physics Letters, 2005
- White organic light-emitting diodes based on 2,7-bis(2,2-diphenylvinyl)-9,9′-spirobifluorene: Improvement in operational lifetimeApplied Physics Letters, 2004
- White Organic Light‐Emitting Devices for Solid‐State LightingAdvanced Materials, 2004
- Very high-efficiency and low voltage phosphorescent organic light-emitting diodes based on a p-i-n junctionJournal of Applied Physics, 2004
- White Electrophosphorescence from Semiconducting Polymer BlendsAdvanced Materials, 2004
- Formation cross-sections of singlet and triplet excitons in π-conjugated polymersNature, 2001
- CorrespondenceSynthetic Metals, 1999
- Improved quantum efficiency for electroluminescence in semiconducting polymersNature, 1999
- Highly efficient phosphorescent emission from organic electroluminescent devicesNature, 1998